diff -up openssl-1.0.2k/crypto/rsa/rsa_gen.c.gen-timing openssl-1.0.2k/crypto/rsa/rsa_gen.c

--- openssl-1.0.2k/crypto/rsa/rsa_gen.c.gen-timing	2018-06-18 13:46:24.323138691 +0200

+++ openssl-1.0.2k/crypto/rsa/rsa_gen.c	2018-06-18 14:53:26.361975922 +0200

@@ -1,6 +1,6 @@

 /* crypto/rsa/rsa_gen.c */

 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)

- * Copyright (C) 2013 Red Hat, Inc.

+ * Copyright (C) 2013, 2018 Red Hat, Inc.

  * All rights reserved.

  *

  * This package is an SSL implementation written

@@ -175,14 +175,13 @@ static int FIPS_rsa_builtin_keygen(RSA *

                                    BN_GENCB *cb)

 {

     BIGNUM *r0 = NULL, *r1 = NULL, *r2 = NULL, *r3 = NULL, *tmp;

-    BIGNUM local_r0, local_d, local_p;

-    BIGNUM *pr0, *d, *p;

     BN_CTX *ctx = NULL;

     int ok = -1;

     int i;

     int n = 0;

     int test = 0;

     int pbits = bits / 2;

+    unsigned long error = 0;

     if (FIPS_selftest_failed()) {

         FIPSerr(FIPS_F_RSA_BUILTIN_KEYGEN, FIPS_R_FIPS_SELFTEST_FAILED);

@@ -251,6 +250,12 @@ static int FIPS_rsa_builtin_keygen(RSA *

     if (!BN_is_zero(rsa->p) && !BN_is_zero(rsa->q))

         test = 1;

+    BN_set_flags(r0, BN_FLG_CONSTTIME);

+    BN_set_flags(r1, BN_FLG_CONSTTIME);

+    BN_set_flags(r2, BN_FLG_CONSTTIME);

+    BN_set_flags(rsa->p, BN_FLG_CONSTTIME);

+    BN_set_flags(rsa->q, BN_FLG_CONSTTIME);

+

  retry:

     /* generate p and q */

     for (i = 0; i < 5 * pbits; i++) {

@@ -266,9 +271,9 @@ static int FIPS_rsa_builtin_keygen(RSA *

         if (!BN_sub(r2, rsa->p, BN_value_one()))

             goto err;

-        if (!BN_gcd(r1, r2, rsa->e, ctx))

-            goto err;

-        if (BN_is_one(r1)) {

+        ERR_set_mark();

+        if (BN_mod_inverse(r1, r2, rsa->e, ctx) != NULL) {

+            /* GCD == 1 since inverse exists */

             int r;

             r = BN_is_prime_fasttest_ex(rsa->p, pbits > 1024 ? 4 : 5, ctx, 0,

                                         cb);

@@ -276,8 +281,16 @@ static int FIPS_rsa_builtin_keygen(RSA *

                 goto err;

             if (r > 0)

                 break;

+        } else {

+            error = ERR_peek_last_error();

+            if (ERR_GET_LIB(error) == ERR_LIB_BN

+                && ERR_GET_REASON(error) == BN_R_NO_INVERSE) {

+                /* GCD != 1 */

+                ERR_pop_to_mark();

+            } else {

+                goto err;

+            }

         }

-

         if (!BN_GENCB_call(cb, 2, n++))

             goto err;

     }

@@ -309,9 +322,9 @@ static int FIPS_rsa_builtin_keygen(RSA *

         if (!BN_sub(r2, rsa->q, BN_value_one()))

             goto err;

-        if (!BN_gcd(r1, r2, rsa->e, ctx))

-            goto err;

-        if (BN_is_one(r1)) {

+        ERR_set_mark();

+        if (BN_mod_inverse(r1, r2, rsa->e, ctx) != NULL) {

+            /* GCD == 1 since inverse exists */

             int r;

             r = BN_is_prime_fasttest_ex(rsa->q, pbits > 1024 ? 4 : 5, ctx, 0,

                                         cb);

@@ -319,8 +332,16 @@ static int FIPS_rsa_builtin_keygen(RSA *

                 goto err;

             if (r > 0)

                 break;

+        } else {

+            error = ERR_peek_last_error();

+            if (ERR_GET_LIB(error) == ERR_LIB_BN

+                && ERR_GET_REASON(error) == BN_R_NO_INVERSE) {

+                /* GCD != 1 */

+                ERR_pop_to_mark();

+            } else {

+                goto err;

+            }

         }

-

         if (!BN_GENCB_call(cb, 2, n++))

             goto err;

     }

@@ -355,51 +376,44 @@ static int FIPS_rsa_builtin_keygen(RSA *

     if (!BN_sub(r2, rsa->q, BN_value_one()))

         goto err;               /* q-1 */

+    /* note that computing gcd is not safe to timing attacks */

     if (!BN_gcd(r0, r1, r2, ctx))

         goto err;

-    if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {

-        pr0 = &local_r0;

-        BN_with_flags(pr0, r0, BN_FLG_CONSTTIME);

-    } else

-        pr0 = r0;

-    if (!BN_div(r0, NULL, r1, pr0, ctx))

-        goto err;

-    if (!BN_mul(r0, r0, r2, ctx))

-        goto err;               /* lcm(p-1, q-1) */

-

-    if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {

-        pr0 = &local_r0;

-        BN_with_flags(pr0, r0, BN_FLG_CONSTTIME);

-    } else

-        pr0 = r0;

-    if (!BN_mod_inverse(rsa->d, rsa->e, pr0, ctx))

-        goto err;               /* d */

+

+    {

+        if (!BN_div(r0, NULL, r1, r0, ctx))

+            goto err;

+

+        if (!BN_mul(r0, r0, r2, ctx)) /* lcm(p-1, q-1) */

+            goto err;

+

+        if (!BN_mod_inverse(rsa->d, rsa->e, r0, ctx)) /* d */

+            goto err;

+    }

     if (BN_num_bits(rsa->d) < pbits)

         goto retry;             /* d is too small */

-    /* set up d for correct BN_FLG_CONSTTIME flag */

-    if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {

-        d = &local_d;

-        BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);

-    } else

-        d = rsa->d;

+    {

+        BIGNUM *d = BN_new();

-    /* calculate d mod (p-1) */

-    if (!BN_mod(rsa->dmp1, d, r1, ctx))

-        goto err;

+        if (d == NULL)

+            goto err;

+        BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);

-    /* calculate d mod (q-1) */

-    if (!BN_mod(rsa->dmq1, d, r2, ctx))

-        goto err;

+        if (/* calculate d mod (p-1) */

+            !BN_mod(rsa->dmp1, d, r1, ctx)

+            /* calculate d mod (q-1) */

+            || !BN_mod(rsa->dmq1, d, r2, ctx)) {

+            BN_free(d);

+            goto err;

+        }

+        /* We MUST free d before any further use of rsa->d */

+        BN_free(d);

+    }

     /* calculate inverse of q mod p */

-    if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {

-        p = &local_p;

-        BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME);

-    } else

-        p = rsa->p;

-    if (!BN_mod_inverse(rsa->iqmp, rsa->q, p, ctx))

+    if (!BN_mod_inverse(rsa->iqmp, rsa->q, rsa->p, ctx))

         goto err;

     if (fips_rsa_pairwise_fail)

@@ -431,6 +445,17 @@ static int rsa_builtin_keygen(RSA *rsa,

     BIGNUM *pr0, *d, *p;

     int bitsp, bitsq, ok = -1, n = 0;

     BN_CTX *ctx = NULL;

+    unsigned long error = 0;

+

+    /*

+     * When generating ridiculously small keys, we can get stuck

+     * continually regenerating the same prime values.

+     */

+    if (bits < 16) {

+        ok = 0;             /* we set our own err */

+        RSAerr(RSA_F_RSA_BUILTIN_KEYGEN, RSA_R_KEY_SIZE_TOO_SMALL);

+        goto err;

+    }

 #ifdef OPENSSL_FIPS

     if (FIPS_module_mode()) {

@@ -483,45 +508,55 @@ static int rsa_builtin_keygen(RSA *rsa,

     if (BN_copy(rsa->e, e_value) == NULL)

         goto err;

+    BN_set_flags(rsa->p, BN_FLG_CONSTTIME);

+    BN_set_flags(rsa->q, BN_FLG_CONSTTIME);

+    BN_set_flags(r2, BN_FLG_CONSTTIME);

     /* generate p and q */

     for (;;) {

         if (!BN_generate_prime_ex(rsa->p, bitsp, 0, NULL, NULL, cb))

             goto err;

         if (!BN_sub(r2, rsa->p, BN_value_one()))

             goto err;

-        if (!BN_gcd(r1, r2, rsa->e, ctx))

-            goto err;

-        if (BN_is_one(r1))

+        ERR_set_mark();

+        if (BN_mod_inverse(r1, r2, rsa->e, ctx) != NULL) {

+            /* GCD == 1 since inverse exists */

             break;

+        }

+        error = ERR_peek_last_error();

+        if (ERR_GET_LIB(error) == ERR_LIB_BN

+            && ERR_GET_REASON(error) == BN_R_NO_INVERSE) {

+            /* GCD != 1 */

+            ERR_pop_to_mark();

+        } else {

+            goto err;

+        }

         if (!BN_GENCB_call(cb, 2, n++))

             goto err;

     }

     if (!BN_GENCB_call(cb, 3, 0))

         goto err;

     for (;;) {

-        /*

-         * When generating ridiculously small keys, we can get stuck

-         * continually regenerating the same prime values. Check for this and

-         * bail if it happens 3 times.

-         */

-        unsigned int degenerate = 0;

         do {

             if (!BN_generate_prime_ex(rsa->q, bitsq, 0, NULL, NULL, cb))

                 goto err;

             if (!BN_sub(r2, rsa->q, rsa->p))

                 goto err;

-        } while ((BN_ucmp(r2, r3) <= 0) && (++degenerate < 3));

-        if (degenerate == 3) {

-            ok = 0;             /* we set our own err */

-            RSAerr(RSA_F_RSA_BUILTIN_KEYGEN, RSA_R_KEY_SIZE_TOO_SMALL);

-            goto err;

-        }

+        } while (BN_ucmp(r2, r3) <= 0);

         if (!BN_sub(r2, rsa->q, BN_value_one()))

             goto err;

-        if (!BN_gcd(r1, r2, rsa->e, ctx))

-            goto err;

-        if (BN_is_one(r1))

+        ERR_set_mark();

+        if (BN_mod_inverse(r1, r2, rsa->e, ctx) != NULL) {

+            /* GCD == 1 since inverse exists */

             break;

+        }

+        error = ERR_peek_last_error();

+        if (ERR_GET_LIB(error) == ERR_LIB_BN

+            && ERR_GET_REASON(error) == BN_R_NO_INVERSE) {

+            /* GCD != 1 */

+            ERR_pop_to_mark();

+        } else {

+            goto err;

+        }

         if (!BN_GENCB_call(cb, 2, n++))

             goto err;

     }